Kang Liwen, Wang Shuaiqi, Xu Qiaohong, Wu Junyan, Wu Yuechuan, Huang Limei, Chen Qiushui, Lin Zhenghuan
Fujian Key Laboratory of Polymer Materials, College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007, China.
College of Chemistry, Fuzhou University, Fuzhou 350108, China.
Inorg Chem. 2024 Apr 15;63(15):7053-7062. doi: 10.1021/acs.inorgchem.4c00693. Epub 2024 Apr 4.
Low-dimensional organic-inorganic hybrid perovskites (OIHPs) have shown significant potential in the optoelectronic field due to their adjustable structure and properties. However, the poor air stability and flexibility of the OIHP crystals limit their further development. Herein, three OIHP crystals have been synthesized using cadmium chloride and the isomer of phenylenediamine as raw materials. Mn doping turns on the red-light emission of Cd-based OIHPs at around 625 nm. Interestingly, the organic ligands with different steric hindrance can induce a transition of the OIHP structure from two dimensions (2D) to one dimension (1D), thereby regulating the quantum yield of red luminescence in the range of 38.4% to nearly 100%. It is found that the surface-exposed amino groups are easy to oxidize, resulting in the instability of these OIHP crystals. Therefore, poly(lactic acid) (PLA) is selected to passivate OIHPs through hydrogen bonding between C═O of PLA and -NH on the surface of OIHPs. As a result, the production of OIHP-based flexible films with highly efficient and stable red emission can be obtained after being encapsulated by PLA. They demonstrate enormous application potential in flexible X-ray imaging. This study not only realizes stable perovskite films but also provides an effective design idea for red flexible scintillators.
低维有机-无机杂化钙钛矿（OIHPs）因其可调节的结构和性质在光电子领域展现出巨大潜力。然而，OIHP晶体较差的空气稳定性和柔韧性限制了它们的进一步发展。在此，以氯化镉和苯二胺异构体为原料合成了三种OIHP晶体。锰掺杂开启了基于镉的OIHPs在625nm左右的红光发射。有趣的是，具有不同空间位阻的有机配体可诱导OIHP结构从二维（2D）向一维（1D）转变，从而将红色发光的量子产率调节至38.4%至近100%的范围内。研究发现，表面暴露的氨基容易氧化，导致这些OIHP晶体不稳定。因此，选择聚乳酸（PLA）通过PLA的C═O与OIHPs表面的-NH之间的氢键对OIHPs进行钝化。结果，用PLA封装后可得到具有高效稳定红色发射的基于OIHP的柔性薄膜。它们在柔性X射线成像中显示出巨大的应用潜力。本研究不仅实现了稳定的钙钛矿薄膜，还为红色柔性闪烁体提供了一种有效的设计思路。
